feat: Initial implementation of FitTrack Report Generator

This commit introduces the initial version of the FitTrack Report Generator, a FastAPI application for analyzing workout files.

Key features include:
- Parsing of FIT, TCX, and GPX workout files.
- Analysis of power, heart rate, speed, and elevation data.
- Generation of summary reports and charts.
- REST API for single and batch workout analysis.

The project structure has been set up with a `src` directory for core logic, an `api` directory for the FastAPI application, and a `tests` directory for unit, integration, and contract tests.

The development workflow is configured to use Docker and modern Python tooling.

tests/unit/test_workout_data.py

@@ -0,0 +1,84 @@
+from datetime import datetime, timedelta
+import pandas as pd
+from src.core.workout_data import WorkoutData, WorkoutMetadata, PowerData, HeartRateData, SpeedData, ElevationData
+
+def test_workout_metadata_creation():
+    metadata = WorkoutMetadata(
+        start_time=datetime(2023, 1, 1, 10, 0, 0),
+        duration=timedelta(hours=1),
+        device="Garmin",
+        file_type="FIT"
+    )
+    assert metadata.start_time == datetime(2023, 1, 1, 10, 0, 0)
+    assert metadata.duration == timedelta(hours=1)
+    assert metadata.device == "Garmin"
+    assert metadata.file_type == "FIT"
+
+def test_power_data_creation():
+    power_data = PowerData(
+        raw_power_stream=[100.0, 150.0, 200.0],
+        average_power=150.0,
+        normalized_power=160.0,
+        intensity_factor=0.8,
+        training_stress_score=75.0,
+        zone_distribution={"Zone 2": "30min"}
+    )
+    assert power_data.average_power == 150.0
+    assert power_data.raw_power_stream == [100.0, 150.0, 200.0]
+
+def test_heart_rate_data_creation():
+    hr_data = HeartRateData(
+        raw_hr_stream=[120, 130, 140],
+        average_hr=130.0,
+        max_hr=180,
+        zone_distribution={"Zone 3": "20min"}
+    )
+    assert hr_data.average_hr == 130.0
+    assert hr_data.raw_hr_stream == [120, 130, 140]
+
+def test_speed_data_creation():
+    speed_data = SpeedData(
+        raw_speed_stream=[5.0, 6.0, 7.0],
+        average_speed=6.0,
+        max_speed=8.0
+    )
+    assert speed_data.average_speed == 6.0
+
+def test_elevation_data_creation():
+    elevation_data = ElevationData(
+        raw_elevation_stream=[100.0, 110.0, 105.0],
+        total_ascent=20.0,
+        total_descent=15.0,
+        max_elevation=110.0,
+        min_elevation=95.0
+    )
+    assert elevation_data.total_ascent == 20.0
+
+def test_workout_data_creation():
+    metadata = WorkoutMetadata(
+        start_time=datetime(2023, 1, 1, 10, 0, 0),
+        duration=timedelta(hours=1),
+        device="Garmin",
+        file_type="FIT"
+    )
+    power_data = PowerData(average_power=150.0)
+    hr_data = HeartRateData(average_hr=130.0)
+    speed_data = SpeedData(average_speed=25.0)
+    elevation_data = ElevationData(total_ascent=100.0)
+    time_series = pd.DataFrame({"timestamp": [datetime(2023, 1, 1, 10, 0, 0)], "power": [150]})
+
+    workout_data = WorkoutData(
+        metadata=metadata,
+        time_series_data=time_series,
+        power_data=power_data,
+        heart_rate_data=hr_data,
+        speed_data=speed_data,
+        elevation_data=elevation_data
+    )
+
+    assert workout_data.metadata.file_type == "FIT"
+    assert workout_data.power_data.average_power == 150.0
+    assert workout_data.heart_rate_data.average_hr == 130.0
+    assert workout_data.speed_data.average_speed == 25.0
+    assert workout_data.elevation_data.total_ascent == 100.0
+    assert not workout_data.time_series_data.empty